A police officer loses his cool and tells a protester to stop rioting because he has known him since he was a boy - in a dramatic exchange during the height of the Ferguson unrest.

Officer Greg Casem screamed at the man in his 20s to stop destroying the community they both grew up in.

He was unable to contain his emotion and, as his voice cracked, he said: ‘I’ve known you for a long time bro... 25 years I’ve been here. Twenty five years!’

The extraordinary moment - captured in pictures which have come to light today - gives an insight into how hard it has been for Ferguson police to watch their own city burn.

These exclusive photos were taken on the second night of unrest after a grand jury decided not to indict Ferguson police officer Darren Wilson.

Offcer Greg Casem comes close to cracking during the riots as he comes faces to face with a demonstrator who he had known since childhood

'You’re killing us! We’re not killing y’all, so stop killing us!’ the 20-something protesters shouted. Officer Casem said: ‘I’ve known you for a long time bro. A long time. Since you were this big [moving hand to waist height]’.

The confrontation shows the toll on officers of the riots in a community where some have served for many years

'Twenty five years I’ve been here. Twenty five years!’ the officer said as he came close to tears

Officer Casem, who was not wearing full protective gear, has served in Ferguson for 25 years

He shot dead Michael Brown, an unarmed black teenager, on August 9 sparking violent unrest that returned last week when no indictment was handed down.

Rioters smashed up most of the historic downtown street and burned more than a dozen buildings during a night of mayhem.

During the violence last Tuesday they also set alight to a police car and smashed the windows of City Hall during skirmishes around the Ferguson police station.

Immediately afterwards officer Casem got into the row with the protester as he pointed to the carnage in front of him.